9 percent of the mammals in the Western Hemisphere, 40 percent in some areas, are unlikely to move their range fast enough to avoid extinction.
Previous studies have looked into where mammals will move as their environments become unlivable from the changing climate. But a new study by the University of Washington questions whether they will actually being able to move fast enough to escape extinction at all.
The lead author of the study, Carrie Schloss, a University of Washington research analyst in environmental and forest sciences, is quoted as saying:
“We underestimate the vulnerability of mammals to climate change when we look at projections of areas with suitable climate but we don’t also include the ability of mammals to move, or disperse, to the new areas.”
Co-author Joshua Lawler, a University of Washington associate professor of environmental and forest sciences, says that more than half of the mammals that have previously been projected to expand their ranges will actually have them reduced.
This is especially true for primates, many of which are already nearing extinction, including tamarins, marmosets, spider monkeys, and howler monkeys. Shrews and moles are also likely to move far too slowly to fare well.
The animals that likely will expand their ranges are wolves, coyotes, the family that includes deer and caribou, and the one that includes anteaters and armadillos.
“U of Washington: The percentage of mammal species unable to keep pace with climate change in the Americas range from zero and low (blue) to a high of nearly 40 percent (light orange).”
The study included 493 different mammals, from the size of the moose, to the shrew. The only factor considered was climate change itself, not the competition and diseases that will come with it.
The research was done by comparing the necessary speeds of migration from different climate models with the speed that a species is able to disperse. An example being that the short reproduction cycles of a mouse allows for good dispersal even though they are small animals, while mammals that spend years raising their young are far less mobile, even though they are generally larger animals.
Other factors include their environments — while an animal that lives in the mountains can simply move to higher elevations, animals living in a rain forest on flat ground must move much further distances to see a change in climate to the same degree.
Primates, being animals with long reproduction cycles, and also in a less varied environment, are likely to face reductions in their range by about 75 percent.
“Our figures are a fairly conservative — even optimistic — view of what could happen because our approach assumes that animals always go in the direction needed to avoid climate change and at the maximum rate possible for them,” Lawler said.
The research also left out the vast influences of human development getting in the way of the animals’ movements. Many animals avoid the noisy, dangerous areas of human development.
“I think it’s important to point out that in the past when climates have changed — between glacial and interglacial periods when species ranges contracted and expanded — the landscape wasn’t covered with agricultural fields, four-lane highways and parking lots, so species could move much more freely across the landscape,” Lawler said.
“Conservation planners could help some species keep pace with climate change by focusing on connectivity — on linking together areas that could serve as pathways to new territories, particularly where animals will encounter human-land development,” Schloss said. “For species unable to keep pace, reducing non-climate-related stressors could help make populations more resilient, but ultimately reducing emissions, and therefore reducing the pace of climate change, may be the only certain method to make sure species are able to keep pace with climate change.”
Source: University of Washington
Image Credits: C Schloss/University of Washington